Roof-Top Rainwater Harvesting Best Practices Guide - International ...

5 Replicability Factors
The application of rainwater harvesting
technologies varies widely, according to
numerous factors which are context-specific.
Factors enabling replicability of any roof-top RWH
technology include the following:
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High degree of community involvement
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Locally available skills
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Cost
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Availability of materials
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Suitable climactic conditions
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Market/demand for additional tanks
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Resource mobilization from multiple
stakeholders
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Training and demonstrations
For project success and sustainability, proponents
must consider these in the planning/inception
stages.
A key factor in ensuring sustainability of the
roof-top RWH systems is community ownership.
Projects teams must look for ways to extend
the impact of the intervention, post project
handover. Conducting a willingness-to-pay study
is recommended to help establish the feasibility
of the project, and the prospects for increasing
the adoption of roof-top RWH as a water supply
solution after project completion.
Figure 7: Willingness-to-Pay Study
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A willingness-to-pay study, conducted by
IRD Zimbabwe, concluded that 5% to 15% of
Chitungwiza’s 300,000 homeowners are willing to
pay more than $1,000 for a standard Roof-top RWH
system, while up to 25% of the homeowners are
willing to pay $500.
ɇ ɇ This indicates the potential demand of 6,000 to
18,000 Rainwater Harvesting Units equating to $6-8
million in revenue for local businesses and local
industry.
Willingness-to-pay studies help projects to
develop strategies for:
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Creating linkages with credit for homeowners
to finance the systems, for example, through
affordable payroll deductions. Through links
to financial institutions, it is possible to create
credit schemes for people to purchase an entire
system and pay back over a period of time.
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Establishing the need for financial mechanisms
to support the demand and income levels of
interested households
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The need to demonstrate the market
opportunity. Links with private sector
Roof-Top Rainwater Harvesting Best Practices Guide 21